Extensible ladder-tower



1 (No Model.) 4 sheets-sheet 1. 1

H. HOFFMANN. EXTENSIBLB LADDER TOWER.

No. 526,318. Patented Sept. 18, 1894.

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4:eXTBNsIBm LADDER TOWER.

Patented Sept. 18, 1894. Edt

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t UNITED STATES PATENT OFFICE..

HENRY HOFFMANN, OF MINNEAPOLIS, MINNESOTA.

EXTENSIBLE LADDER-TOWER.

SPECIFICATION forming part of Letters Patent No. 526,318, dated September 18, 18914. Application filed May 1, 1894. Serial No. 509,645. (No model.)

To all whom it may concern.-

Be it known that I, HENRY HoFFMANN,a citizen of the United States, residing at Minneapolis, in the county of Hennepin and State of Minnesota, have invented certain new and useful Improvements in Extensible Ladder- Towers; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

My invention has for its object to provide an improved ladder tower, for firemens use.

To this end, my invention consists of certain novel devices and combinations of devices, which will be hereinafter fully described and be deined in the claims.

The accompanying drawings illustrate my invention, wherein, likeletters and figures referring to like parts- Figure l is a side elevation, showing the ladder-tower, as mounted on a truck, laid down into its horizontal position. Fig.` 2 is a right side elevation, and Fig. 3 is a front elevation of the ladder-tower, detached. Fig. 4 is a Vertical section, from front to rear, on the line X X of Fig. 3. Fig. 5 is aright side elevation, showing the parts as drawn out into their most extended position, the view being on a smallscale, as compared with the other figures. Fig. 6 is a detail in front elevation, with some parts broken away, showing the catches for locking the secondand third sections together, to move as one, and the triplevers for releasing the same. Fig. :7 is a cross section, on the line X2 X2 of Fig. 5; and Fig. 8 is a plan View of the top section, detached.

The truck a, on which the ladder-tower is to be mounted, may be of any suitable con struction; and the ladder-tower may be pivotally connected thereto, in any suitable way, which will afford the necessary power for turning the same from its horizontal to its upright position, orvice versa. For purposes of illustration merely, the ladder tower is shown as connected to the truck, by a hinge b, secured to abase-plate b.

The ladder-tower is shown, as composed of three sections, marked with the numerals 1, 2 and 3. Each of these ladder sections has several sides, four as shown, the several memthey are the same as in the lower section, with the exception of the fact, that the rangs at the back are omitted, for a purpose which will presently appear, and that the rungs at the lower end of the said second section, are formed integral with cross-braces of yoke like form, constituting a single casting c3, the sides of which make up the rungs for the sides of the tower, and the central portion and the curved portions of which serve to rigidly brace the back standards from the other parts of the structure. The front rung at the same level as the casting c3, is similar to the rungs c2, employed for the steps of the lower or base section and all of the second section, except the lower member made up of the castings c3. All the rung-members of the upper section 3, are made up of castings c3, like that just described, cooperating with individual rungs c2, at the front o'f said section.

\ To the back of the base section l, and the second section 2, at the upper ends of the same, are lixed inwardly projecting sheave brackets d of crane-like form, the upper portions of which may beV formed integral with the rear sections of the cap-frames c. In

these brackets d, are mounted sheaves d d3.

The lower casting c3 of the second section, is provided with a sheave d2, at its center; and the lower casting c3 of the upper section, is provided at its center, with an` eye-lug or hook d4. On brackets d5 projecting fromthe standards of the lower section l, is mounted a windlass-roller d, from which extends a cable CZ7, which passes over the sheaves d d2 d3, in the order named,and has its outermost end secured to the eye-lug d4, on the base p The windlass roller d6 is provided with an operating crankcasting'c3 of the top section.

handle d8 and a ratchet dg, with which ratchet IOO a retaining pawl d co-operates, in the usual way, for holding the windlass-roller, wherever set.

The top section 3, is provided with spring catchesf (see Fig. 6) which are adapted to engage under inside rungs f', fixed to the second section, near the top of the same, and serve to limit the "upward movement of the top section, on the second section and to support the same, when the said'parts are engaged from the second section. Bell crank levers f2 are carriedby the second section, the short arms of which are in position to bear against the outer surfaces of the springcatches f, for releasing the same from the rungs f', at will, as when it is desired to lower the ladder. An operating flexible connection f3, composed of rope or other suitable material, has branches f4 f5, connected to the long arms of the bell-cranklevers f2; for permitting an operator, at the windlass level, to pull the said trip-levers inward and release the catchesf from the rungs f', at will. The

rope branch f5 passes over suitable guidesheaves f6, for properly directing the pull of the rope on the trip-lever. The body portion of the said rope is shown as passing through suitable guide-keepers f7, on the ladder section 2. With this construction, on the initial action of the windlass, the top Vor third section will be first moved upward to its limit, when by the camming action of the parts,

" the catches f will engage with the inner rungs the hose.

f on the second section of the ladder; and thereupon, on the further movement of the windlass, the two sections 2 and 8, will be moved upward together, and be held by the cable and the windlass.

fOn the reverse motion of the windlass, the two upper sections will be lowered together to the downward limit of the second section; and when this point is reached, the trip-levers f2 will be operated, by the trip-ropej, thereby permittingthe upper section to be lowered to its downward limit, under the further unwinding motion of the windlass. The fact that the second section is open at its back and is provided with the yoke-like casting c3, at thebottom, and the fact that all the rungs and cross braces of the upper section are composed of these yoke-like castings c3, aords the necessary clearance, for permitting the two movable sections to pass the sheave brackets d d. These yoke-like castings c3 on the upper section, serve to divide the tower-shaft into two compartments g g., inthe back member of which extends the cables m, for eectinga telescopin g movement; and in the front member g of which, is located a hose section h, which may be. secured thereto in any suitable way, such as by keeper-brackets h', fix-ed to the ladder-section and embracing With this construction, the hose section h will be movable with the uppermost yladder section, and will be always available forconnection with the supply and delivery sections of the water-hose; and in virtue of the casting c3, the said hose section his afforded a free passage-way, in the compartment g which is protected from interference from the laddercables. As hereinbefore stated, the lower ladder section is shown as provided with a rectangular base-plate b', to which the said ladder section I, is hinged or pivoted, as shown Vat b, with the said base b' shown as secured to the truck, for purposes of illustration, in Fig. l. As shown in the other views, the base section b is provided with detents b?, which are engageable by spring-catches b3, fixed to the said lowermost ladder section, for holding the ladder in its upright position, `in respectto the saidbase-L plate b.' As before stated, these parts b to b3 inelusive, are simply illustrative of some means,-

for securing the ladder-tower tothe truck, with freedom for turning the same from the horizontal to the vertical position. In `practice, these parts would have to be of avmuch` more substantial character than is here shown; and for convenience and quick handling, power devices would have to be provided, for effecting this pivotal movement of f the tower. v

From the foregoing description and an inspection of the drawings, it will be seen, that the second section telescopes Within the first section, and the third section within thesecond section; that all the sections are selfbracing and that the whole tower is self-supporting on the base section. I believe this to be a new principle of construction for extension ladders. As shown, the dierent sections are four-sided, and this is the desirable construction.; but they might be made selfsupporting, if composed of three sides or if constructed in the form of cylindrical shell. The multiple side-ladder tower, is not only an advantage in this respect of being selfsupporting, but affords a large amount of lad- `der surface available for use by an-umber of different remen, when necessary. The whole structure is comparatively simple audgcheap to make, and is capable of quick manipulation for the purposes required. Changes, of course, might be made in the details of the construction, without departing from the spirit of my invention.

In practice, the ladder-tower may, of course, have any desired number of telescoping sections, to afford the requisite elevation. For ordinary service, a single sliding section is sufficient; in which event, the intermediate section 2 would be dispensed with andthe upper section 3 be made to telescope directly with the basesection 1.

What I claim, and desire to secure by Letters Patent of the United States,is as follows:

l. The combination with the multiple sided i ladder-tower composed of telescoping sections, of'a windlass on the lowermost or-base section, sheaves on inwardlyproj ectingbrackets fixed to all except the uppermost section,

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and a single cable running over said sheaves to said windlass and operative to extend the ladder, substantially as described.

2. The combination with the multiplesided ladder tower composed of telescoping sections, of the windlass on the base sections, hoisting sheaves on all except the top section, a single cable running over said sheaves to said windlass, means for locking two or more of the telescoping sections to move together as one, and means for unlocking the same to permit the upper to be lowered on the next lower elevated section, substantially as described.

3. The extensible ladder-tower composed of telescoping sections, the upper member of which is provided with central cross braces dividing the shaft into two vertical compartments, a hose section secured to said upper ladder section in one of said compartments and hoisting cables, for said upper section, working in the other of said compartments, substantially as described.

4. In the multiple sided tower-like ladder, the combination with the crane-like sheave brackets, of the yoke-like center braces on the movable ladder sections, for affording clearance to pass said sheave brackets, substantially as described.

5. The combination with the ladder section 3, having the spring catches f, of the ladder section 2 having the detent rungs f', the pivoted bell-crank trip levers f2, for releasing said catches with a camming action, and the trip rope or connection f3 f4 f5, all arranged and operating, substantially as described.

6. The combination with the ladder sections 1, 2 and 3, of the sheave brackets d, secured to the sections l and 2, and the yoke-like castings c8 forming all the cross braces and side rungs'of the upper section, and the lower` brace for the second section 2, substantially as described.

In testimony whereof Iaflix my signature in presence of two witnesses.

HENRY HOFFMANN.

Witnesses:

JAS. F. WILLIAMSON, E. L. ELMoRE. 

